Shot cartridge



March 6, 1928. 1,661;609

- H. GREENER SHOT CARTRIDGE Filed April 11, 1927 Fig.1.

Patented Mar. 6, 1928.

umrsa srArEs P ATE Q-FF HARRY. GREENER, F BIRMINGHAM, ENGLAND.

SHOT' CARTRIDGE.

Application filed April 11, 1927; Serial. Nb; 1823848, and imGrcat Britain April 1 1926.

According to the present invention, which relates toshot cartridges for use with sporting guns, the portion of the case that contains the shot-charge 1s, for the whole or 5 the greater part of its length, reduced in shot-wad end,- and this'bottle-neck portion contains the whole or the greater partof the charge of shot and the shot-wads whilst the powder or propellant charge and powder wads contained in the larger or body part of the case; the shoulder formed by such necking where the bottleneck joins or merges into the main body being utilized to retain the powder wads in place in front of the propellant charge and to impose resistance on the displacement of such wads. WVith such a cartridge, when loaded into the chamber of a gun, the neck or reduced portion is surrounded by an annular space.

The accompanying drawing shows a shot cartridge in accordance with an application of my invention, Figure 1 being an elevation of the same, Figure 2 a cross-section through the neck (the shot being omitted) and Figure 3 a complete longitudinal section of the cartridge on the dotted line 33, Figure 2.

Preferably necking or reduction of the shot-containing part a of the case a is performed after the loading of the propellant charge 6 and the seating of the powder wads c on the latter, and to facilitate this necking by a spinning-down operation (particularly in a paper case) the part that is to be spun down or necked and shouldered over the powder-wads may first be formed with a series of longitudinal grooves or inward indentations along the lines d, and these grooved portions are, in the course of the necking or spinning down operation, closed up or crimped, or transformed into closed gussets (see Figure 2) which gives the bottleneck the capacity of readily expanding to its original diameter when the cartridge is fired. e is the shot charge and f the shot wads, which are held in place by the turnover 7 of the neck. Such bottle-necked shot cartridges are intended to be used in shot guns whose barrels have the ordinary parallel-bored or cylindrical chambers so that the chamber does not resist expansion of the neck on discharge, and a suitable red'uction would be one inwhich the neck is approximately two bore sizes smaller than the body of the case. Thus a cartridge fora lit-bore g-Lur may be reduced over the shotcontaining neck to l l-bore; or the reduc tions may be to 16-bore or even smaller in cartridges for loading with large charges; it being? understood'that the greater the reduction. over the shot, the wideror more pronounced" is the annular shoulder or stepping, over the powder wads, and the. greater the resistance imposed on the saidwaids by the necking.

The principal advantage realized by the said invention is reduction of the pressure on the starting of the shot charge; the resistance set up by the shouldering of the case over the powder wads being such as to control the combustion of the powder in a manner which permits the column of shot to leave the necking of the case and become shortened in length on filling up the full diameter of the barrel-bore before the powder gases can develop higher or increasing pressures.

Thus the improved shot cartridge realizes better ballistics than the usual type of cylindrical cartridge, and incidentally, by reason of the necking, it is easier to load into a gun and easier to eject. The forward end is also easily distinguished by touch or feeling owing to the said necking.

The better ballistics may be utilized to improve patterns, or to obtain higher velocities with improved patterns, or to permit of highly increased velocities being realized by the use of large charges of powder or propellant. These improvements in shotting qualities are attributable to the fact that the formation and the manner of loading the powder and shot charges and wads permits, on ignition of the powder charge, of the shot making a true rolling movement under an initial or starting pressure which is or may be less than the maximum pressure developed by the same powder charge in an ordinary case; this rolling of the shot being maintained during the passage of the shot from the cartridge into the barrel, which prevents the charge of shot being compacted or jammed together and avoids the distortion (such as occurs with ordinarily loaded cases) of the individual pellets from their true spherical form. Thus, given a suitable proportioning of the bottle-necking and the body of the case, it

is possible to realize low initial resistance (which results in lower inital pressures and lower initial velocity) during the passing of the rolling shotfrom the cartridge case into the barrel and to provide for a gradual rise of pressure to the maximum as the shot column fills up and shortens in the said barrel. Consequently, although the shot 'ac quires a high velocity, the development of the powder, gas pressure is gradual or increases progressively as the shot passes along the-barrel without at' any time risingunduly in proportion to the velocity attained. V V

The'shot wads may be retained in the bottle-neck by a light turn-over so that in ef'ect there ispractically no resistance over the shot-charge; the effective resistance in' the cartridge being imposed directly on the powder-wads by the shouldering of the case over the latter during the reduction of the I neck.

ameter corresponding to that of a gun chamber, said shell also having a diametrically reduced neckprovided with longitu dinal crimpings and a shoulder connecting said neck and said body, a powder charge in said body, a shot charge in said. neck and wads between said charges, the foremost of which bears against said shoulder, the

-' said cartridge when loaded in a gun cham- HARRY GREENER. 

